Mineral oil composition



. etc.

Patented Jan. 11, 1949 MINERAL om COMPOSITION Edward A. Oberright, Woodbury, N. 1., assignor to Socony-Vacuum Oil Company, Incorporated, a corporation of New York No Drawing. Application July 6,1945,

Serial No. 603,593

1 This invention has to do in a general way with mineral oil compositions and is more particularly 4 related to compositions comprised of mineral oil and a minor proportion of an added ingredient which will improve the oil in one or more important respects. 1

It is well known to those familiar with the art that mineral oil fractions refined for their various uses are in and'of themselves usually de ficient in one or more respects so that their practical utility is limited even in the particular field for which they have been refined. For example, mineral oil fractions refined for use as lubricants have a tendency to oxidize under conditions of use, with the formation of sludge or acidic oxidation products; also, the lighter fractions such as gasoline and kerosene tend to oxidize with the formation offcolor bodies, gum, etc. In order to prevent the formation of these products and thereby extend the useful life of the oil fraction, it is common practice to blend with such oil fraction an additive ingredient which will inhibit oxidation, such ingredients being known to the trade as oxidation-inhibitors,

antioxidants, sludge inhibitors, gum inhibitors,

It is also the practice to add other ingredients to mineral oil fractions for the purpose of improving oiliness" characteristics and the wearreducing action of such mineral oils when they are used as lubricants, particularly when the oils are used for the purpose of lubricating metal 6 Claims. (Cl. 252-415) the piston rings'to become stuck in their -slots and which fill the slots in the oil ring or rings,

thus materially reducing the efficiency of the engine. Ingredients have been developed-which,

when added to the oil, wil1 reduce this'nat'ural tendency of the-oilto form deposits which inter fere' with the function of the piston rings.

It has also been discovered that certain types of recently-developed hard metal alloys,gsuch 2 those used for fuel purposes, particularly in,in

surfaces which are engaged under extremely high pressures and at high rubbing speeds.

Various other ingredients have been developed for the purpose of depressing the pour point of mineral oil fractions which have been refined for use as lubricants. Most refining treatments provide oils containing a small amount of wax which, without the added ingredient, would tend to crystallize at temperatures which render the oil impracticable for use under the low temperature conditions. Additive agents have also been developed for improving the viscosity index -of lubricating oil fractions. In the case of internal combustion engines, particularly those operating with high cylinder pressures, there is a decided tendency for the ordinary lubricating oil fracas cadmium-silver alloyv bearings,*are attacked by ingredients incertain types of oils,- par-v ticularly oils of high viscosity'index obtained by variousmethods of solvent refining. This corrosive action 'on such alloys hasle'd. to thedevelopment of ,corrosion inhibitors which may be used in solvent-refined oils to protect suchbearternal combustion-engines, it has been found that the combustion characteristics of thef'fuel may be controlled and improved byadding minor" I proportions of various improving agentsthereto.

The various ingredients which have been developed for use in mineral 'oil fractions to im.-

prove such fractions in the several characteristicsenumerated above are largely specific to their particular applications. Therefore, it has been the practice to add a separate ingredient for each of the improvements which is to be effected.

The present invention is predicated upon the discovery of a group or class of oil-solublereaction products or compounds which, when added to mineral oil fractions in minor proportions, will improve the oil fractions in several respects.

The novel addition agents contemplated by this invention as a multifunctional improvers for mineral oils are oil-soluble, phosphorus-containing and phosphorusand sulfur-containing reaction products obtained by reacting an aldehyde, a heterocyclic amine and a hydroxyaromatic compound to form a condensation product and thereafter reacting the latter with either: a phosphorus halide to form, a phosphorus-containing reaction product; a phosphorous sulfide or thiohalide to forma phosphorus and sulfurQ-containing reaction product; or a phosphorus halide, phosphorus thiohalide or a phosphorus sulfide and a sulfurizing material such as elementary 3 sulfur, a sulfur halide or a mixture thereof to form a phosphorusand sulfur-containing reaction product. Metal salts of these phosphoruscontaining, and phosphorusand sulfur-containing, reaction products are contemplated herein.

The condensation products obtained by reacting an aldehyde, aheterocyclic amine and a hydroxyaromatic compound are represented by the general formula.

' on I Rel wherein A is an aromatic nucleus, either monoor poly-cyclic; R is either hydrogen or an alkyl, aralkyl, alkaryl, aryl, cycloalkyl, alkoxy or aroxy group; a represents the number of R groups attached to an aromatic nucleus A, and is an integer from to 4; X is a substituent such as an amino, nitro, hydroxyl, carboxyl or halogen group or the like; 1) represents the number of X groups attached to an aromatic nucleus A and is either 0 or 1; Y is a secondary heterocyclic amine group, attached at a secondary (heterocyclic) nitrogen atom to the carbon atom of a group; and 0 represents the number of H t Y groups attached to an aromatic nucleus A and is an integer from 1 to 3. It will be clear that when A is a phenyl nucleus, the sum of a, b, and c will not exceed and when A is a naphthalene nucleus or other polycyclic nucleus, the sum may exceed 5.

Aldehydes contemplated by the present invention are the aliphatic aldehydes, typified by formaldehyde (such as trioxymethylene), acetaldehyde, and aldol (B-hydroxy butyraldehyde); aromatic aldehydes, representative of which is benzaldehyde; heterocyclic aldehydes, such as fur'fural; etc. The aldehyde may contain a substituent group such as hydroxyl, halogen, nitro and the like; in short, any substituent which does not take a major part in the reaction. Preference, however, is given to the aliphatic aldehydes, formaldehyde being particularly preferred.

The secondary heterocyclic amines are those characterized by attachment of a hydrogen atom to a nitrogen atom in the heterocyclic group. Representative of the amines contemplated herein are morpholine, thiomorpholine, pyrrole, pyrroline, pyrrolidine, indole, pyrazole, pyrazoline, pyrazolidine, piperidine, phenoxazine, phenthiazine and their C-substituted analogs. Substituent groups,-attached to the carbon atoms of' these amines are typified by alkyl, aryl, alkaryl, aralkyl, cycloalkyl, etc. Preferred of these amines is morpholine.

Representative hydroxyaromatic compounds contemplated 'by the present invention are phenol, resorcinol, hydroquinone, catechol, cresol, xylenol, hydroxyphenyl, benzylphenol, phenylethylphenol, phenol resins, methylhydroxydiphenyl, guiacol, alpha and beta naphthol, alpha and beta methylnaphthol, totylnaphthol, xylylnaphthol, benzylnaphthol, anthranol, phenylmethylnaphthol, phenanthrol, monomethyi ether of catechol, phenxyphenol, chlorphenol, and the like. Preference in general is to the monohydroxy phenols otherwise unsubstituted, particular preference being given to phenol and alpha and beta naphthol.

The hydroxyaromatic compounds may also contain one or more substituent groups such as carboxyl, halogen, nitro, amino and the like; in short, any substituent which does not take a predominant part in the condensation with the aidehyde and the heterocyclic amine. Preferred of such substituents is a carboxyl group.

As indicated hereinabove, the hydroxyaromatio compound may contain one or more alkyl substituents such as short-chain groups, typified by methyl, ethyl, amyl, etc.; or long-chain, relatively high molecular weight hydrocarbon groups having at least twenty carbon atoms, typified by alkyl groups derived from petroleum wax, which is a predominantly straight-chain aliphatic hydrocarbon of at least twenty carbon atoms. It will be obvious to those skilled in the art that the maximum number of alkyl groups is limited 4 by the number of valences on the aromatic nucleus available for substitution. Naturally, the maximum number of such groups which can be attached to a single aromatic nucleus will vary as the nucleus is monoor poly-cyclic and as the nucleus is otherwise substituted with such groups as carboxy, nitro, amino, halogen and the like.

A typical, and also preferred, alkyl-substituted hydroxyaromatic compound which may be used is a wax-substituted phenol, wax-pheno The term wax" as used herein designates petroleum wax or aliphatic hydrocarbons 0r hydrocarbon groups of the type which characterize petroleum wax. These so-called wax" substituents may be obtained by alkylation of the phenol or hydroxyaromatic hydrocarbon with a relatively high molecular weight aliphatic hydrocarbon or mixture of such hydrocarbons (such'as petroleum wax) by any suitable alkylation procedure such, for example, as by a Friedel-Crafts condensation of chlorinated petroleum wax with phenol.

The condensation products are believed to be formed in the manner indicated in the following equation, wherein formaldehyde, phenol and morpholine are used as illustrations:

In preparing the condensation products, the reactants may be added to each other in any order. A typical procedure involves adding the aldehyde to an alcohol solution of the hydroxyaromatic compound and the heterocyclic amine. The reaction may also be carried out in the presence of other diiuents or solvents such, for example, as benzol, chlorbenzene, tetrachlorethane, mineral oil, etc. used as a diluent, the mineral oil may be retained, rather than separated from the condensation product, thereby providing a mineral oil concentrate which may bereacted with a phosphorus compound of the type mentioned above, or with such a phosphorus compound and a sulfurizing In the event that mineral oil is I zene, chlorbenzene, mineral oil, etc.

- s material ofthe type'indicated above. 011 concentrates of the phosphorus-containing, and phosphor-use and. sulfur-containing, reaction products may be obtained in this manner. Metal salts of these reaction products may similarly be paratively short period. By way of illustration,

the reactants, in quantities such as shown in the following example, may be thoroughly mixed at 2025 C. for several hours and the reaction complated at the reflux temperature of the reaction mixture for an additional period of several hours.

The condensation product may be water washed to assure complete removal of any unreacted amine and this is recommended when the amine is high boiling. In general, however,

the procedure involves distilling off the solvent which also removes any unreacted amine, water of reaction and water added with the reactants (formaldehyde, for example, is generally used in a 37 aqueous solution) As indicated hereinabove, the reaction products contemplated herein may be prepared by reacting a condensation product of the type described above with a phosphorus halide, a phosphorus sulfide or thiohalide, or at least one such phosphorus compound and a sulfurizing material. This reaction is preferably carried out in the presence of an inert diluent such as tetrachlorethane, ben- These diluents-except heavy mineral oils-are removed after the reaction by distillation of the reaction mixture which contains the desired reaction product. When a mineral oil is used as the diluent, however, it may be retained, thereby providing a mineral oil concentrate containing the reaction product.

Temperatures of the order of about 20 C. to about 200 C. are generally maintained when reacting a phosphorus halide with a condensation product. The preferred procedure, however, involves adding a phosphorus halide to a condensation productat room temperature (20-25 C.) and thereafter heating the reaction mixture so formed at the reflux temperature of the diluent for several hours. Related phosphorusand sulfurcontainin'g reaction products, in general, are also prepared under the foregoing conditions by reacting a condensation product with a phosphorus compound and with or without a sulfurizin material. 1

The phosphorus halides and sulfides which may be used herein are represented by the following: PCla, POCla, PSCls, PO15, PzSa, P354, P285, P491, etc. Preferred of these materials are P013 and P285. While only the phosphorus chlorides are recited above, the iodides and fluorides may also be used, but the chlorides are more desirable in view of their lower cost and availability.

As indicated above, the sulfurizing materials are elementary sulfur, sulfur halides and mixtures thereof. Of these materials, sulfur halides are preferred, with sulfur monochloride particularly preferred.

Metal salts of the aforesaid phosphorus-, and phosphorusand sulfur-, containing reaction products, as indicated above, also fall within the corresponding bromides,

scope of the present invention- Any metal may be used the oxide or hydroxide of which (in alcohol solution, if necessary) can be reacted with the intermediate condensation product, or a salt of which can be reacted in alcohol solution with the sodium salt of the intermediate product. Among the metals contemplated for this purpose are: copper, beryllium, magnesium, calcium, strontium, barium, radium, zinc, cadmium, mercury, germanium, tin, lead, vanadium, chromium, manganese, iron, cobalt, nickel, ruthenium, palladium, platinum, aluminum, antimony, arsenic, bismuth, cerium, columbium, gallium, gold, indium, iridium, molybdenum, osmium, rubidium,

selenium, tantalum, tellurium, thorium, titanium,

tungsten, uranium, and zirconium. Preference is given to metals of the alkaline earth group, particularly to barium. As noted above, the metal si preferably introduced by reaction of its oxide or hydroxide with the intermediate condensation product. Where necessary, an alcohol solution of the oxide or hydroxide is used. The metal salts can also be prepared by reacting the sodium salt of the intermediate product with an alcohol $0111 tion of a salt of the desired metal, suchas stannous chloride, lead acetate, thorium nitrate, titanium tetrachloride, etc. I

The phosphorus-containing reaction products are illustrated by the following typical example.

EXAMPLE Fifty grams of wax-phenol (2-18), prepared as described in U. S. Patent No. 2,191,499, and 7.7

grams of morpholine were dissolved in butyl alcohol, and 14.6 grams of Formalin (37%) were added dropwise thereto, addition taking about 20 ture and was removed therefrom, with butyl alcohol and water of reaction and added water of the Formalin used, by distillation to a maximum temperature of 160 C. at 10 mms. pressure. The reaction product thus obtained was wax hydroxy benzyl morpholine (2-18); nitrogen analysis revealed 1.7% nitrogen, compared with a theoretical nitrogen. content of 2.0%.

Thirty grams of wax hydroxy benzyl morpholine (2-18) was blended in 60 grams of mineral oil (S. U. V. of 65 seconds at 210 F.) and heated to 65 C., at which temperature 2.34 grams of PC13 were added dropwise. Tetrachlorethane (200 ccs.) was added in order to provide a uniform reaction mixture. The reaction mixture was then heatedat C. for 2 hours. Any HCl present in the form of an HCl-amine complex in the reaction mixture, was removed by washing the reaction mixture with aqueous ammonia, followed with aqueous acetic acid solution and finally with water until the washings were neutral. Tetrae chlorethane was removed from the Washedreaction mixture by distilling the latter to a maximum temperature of 175 C. at 10 mms. pressure. The reaction product-Product On'eis a 1:2 mineral oil blend and contains 0.58% nitrogen and 0.42% phosphorus.

SOCONY-VACUUM TURBINE TEST Twenty-five cc. samples of a furfural-refined Rodessa crude of S. U. V. of seconds at 100 F. and of blends of this same oil and typical re-.

Table .1

Addition Agent jfi ggg Hours ggfgf N. N. 1 251? None 162 245 17. S 389 Product One. M 166 3 0. 01 2 1, one 6 0.06 24 1, 34s 110 19.0 172 CORROSION Tnsr In this test the reaction product was blended with a Pennsylvania solvent-refined oil of S. U. V. of 53 seconds at 210 F., and a section of a bearing containing a cadmium-silver alloy surface and weighing about 6 grams was added to this blend. The oil was heated to 175 C. for

22 hours while a stream of air was bubbled against the surface of the hearing. The loss in weight of the bearing during this treatment measured the amount of corrosion that had taken place. A sample of the straight oil was subjected to the same test at the same time, and the difierence between the losses in weight of the two bearing sections demonstrated conclusively the effectiveness of the reaction products contemplated herein as corrosion-inhibitors.

Table II Bearing Loss (mgma) Addition Agent Piggfin Inhibited Uninhibited Oil Oil Product One M 4 35 It will be apparent from the foregoing test data that the characterizing materials of this invention are efiective multifunctional oil improving agents.

The improved properties and the degree of improvements efiected may be varied with the aidehyde, heterocyclic amine, hydroxyaromatic compound, phosphorus halide or sulfide, and metal used in their preparation and present in the reaction product.

The amount of improving agent used varies with the mineral oil fractionwith which it is blended and with the properties desired in the final oil composition. These reaction products, and the metal salts thereof, may be added to mineral oil in amounts of from about 0.01% to about 10%, but amounts of the order of 0.1-5% generally provide satisfactory improvement.

It is to be understood that although I have described certain preferred procedures which may be followed in the preparation of the novel reaction products contemplated herein as multifunctional addition agents for mineral oils and have indicated representative reactants for use in their preparation, such procedures and reactants are merely illustrative and the invention is not to be considered as limited thereto or thereby but includes within its scope such changes and modifications as fairly come within the spirit of the appended claims.

.with about 2.5 mols of a condensation product represented by the general formula:

i t group; and 0 represents the number of H L Y 1's groups attached to an aromatic nucleus A and is an integer from 1 to 3.

2. An improved mineral oil composition comprising a mineral oil having in admixture therewith a small proportion, from about 0.01 per cent to about 10 per cent, of an oil-soluble, phosphorus-containing reaction product obtained by reacting, at a temperature between about 20 C. and about 200 C., one moi of a phosphorus compound selected from the group consisting of a phosphorus halide, a phosphorus thiohalide and a phosphorus sulfide, with about 2.5 mols of a condensation product represented by the general formula:

. (ill LII R's-A c it i group; and 0 represents the number of H LY It groups attached to an aromatic nucleus A and is an integer from 1 to 3.

, 3. An improved mineral'oil composition comprising a mineral oil having in admixture there-.

with a small proportion, suiflcient to inhibit said oil against the deleterious effects of oxidation, of an oil-soluble, phosphorus-containing reaction product obtained by reacting, at a temperature between about 20 C. and about 200 0., one moi of a phosphorus halide with about 2.5 mols of a condensation product represented by the general formula:

-OH H li.-J\[(FY] 1'12 wherein A is an aromatic nucleus; R is selected from the group consisting of hydrogen, alkyi, aralkyi, alkaryl, aryl, cycloalkyl, alkoxy and aroxy groups; a represents the number of R groups attached to an'aromatic nucleus A, and is an integer from to 3; R is selected fromthe group consisting of hydrogen, alkyl, alkaryl, aralkyl, cycloalkyl and aryl groups; Y is a morpholine group attached at the nitrogen atom thereof to the carbon atom of they group; and 0 represents the number of groups attached to an aromatic nucleus A-and is an integer from 1 to 3. a

4. An improved mineral oil compositioncomprising a mineral oil having in admixture there- 5. An improved mineraloil'composition comprising a mineral oil having in admixture therewith a small proportion, sufficient to inhibit said oil against the deleterious effects of oxidation, of an oil-soluble, phosphorus-containing reaction product obtained by'reacting, at a temperature between about C. and about 200 0., one mol of phosphorus trichloride with about 2.5 mols ota parailin wax-hydroxy-benzyl morpholine. v

/ 6.-An improved mineral oil composition comprising a mineral oil having in admixture therewith a small proportion, sumcient to, inhibit said oil against the deleterious effects of oxidation, of an oil-soluble, metaland phosphorus-containing reaction product obtained by reacting, at a temperature'between about 20 C, and about 200 C.,-one moi of a phosphorus compound selected 7 from the group consisting of a phosphorus halide,

a'phosphorus thiohalide and a phosphorus suifide, with about 2.5 mols of a'condensation product followed by introduction of metal into the phosphorus-containing reaction product so obtained, said condensation product being represented by the general formula:

wherein A is an aromatic nucleus; R is selected from the group consisting of hydrogen, alkyl, =araikyl, alkaryl, aryl, cycloalkyl, alkoxy. and aroxy groups; a represents the-number of R groups attached to an aromatic nucleus A, and is with a small proportion, suflicient to inhibit said I oil against the deleterious effects of oxidation,

of an oil-soluble, phosphorus-containing reaction product obtained by reacting, at a temperature between about 20 C. and about 200 0., one moi of phosphorus trichloride with about 2.5 mols of a condensation product represented by the general formula:

on H traps] It from the group consisting of hydrogen, ,alkyl, aralkyi, alkaryl, aryl, cycloalkyl, alkoxy and aroxy groups; n represents the number of R. groups attached to an aromatic nucleus A, and is an integer from 0 to 3; R is selected from the group consisting of hydrogen, alkyl, alkaryl, aralkyl, cycloalkyl and aryl groups; Y ls-a morpholine group attached at the nitrogen atom thereof to the car""r atom of the group; and c represents the number of H Ja-r groups attached to aromatic nucleus A and is an nte mfrom 1 to 3,

wherein A is an aromatic nucleus; R' is selected 0 thereof to the carbon an integer f'rom0 to 3; R" is selected from the group consisting of hydrogen, alkyl, alkaryl, ar-

alkyl, cycioalkyl and aryl groups; Y is a morpholine group attached at the nitrogen atom atom of the i C I, group; and 0 represents the number of groups attached to an aromatic nucleus A and g is aninteger from 1 to 3.

EDWARD A. OBERRIGHT.

REFERENCES crrEn The following references are ofrecord in the file of this patent: 1 v

UNITED STATES Certificate of Correction Patent No. 2,459,115. January 11, 1949.

EDWARD A. OBERRIGHT It is hereby certified that errors appear in the printed specification of the above numbered patent requiring correction as follows;

Column 3, line 70, for hydroxyphenyl read hydrozydiphenyl; column 4, line 1, for

phenxyphenol read phenowyphenol column 6, line 19, for si read is;

and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 14th day of June, A. D. 1949.

THOMAS F. MURPHY,

Assistant Uonmissioner of Patents. 

